Color photography



Patented Dec. 23, 1941 2,267,089 Y coma PHOTOGRAPHY John Eggert,Leipzig, and Gerd Heymer, Wolfen, Germany, assignors, by mesneassignments, to General Aniline & Film Corporation, New York, N. Y., acorporation of Delaware Application Dec rn l a Claims.

The present invention relates to the production ci photographicmulti-color pictures.

Une of its objects is a photographic material producing multi-color'component images. An-

ember 2, 1938, Serial No. 113,827 n3 :L l Dccmbef 7,

component color picture has been in thismanner preserved the firstdeveloped layer is mechanically or chemically removed' and then theunderlying layer is developed after the hitherto other object is aprocess of producing multi-color 5 separating layer has been madepermeable in a component images. Further objects will be seen from thedetailed specification `following hereafter.

In the production of three-color components for color photography it hasbeen proposed in U.S.Patent 2,210,146 of which the present applicationis a continuation in part to insert between superimposed emulsion layersintermediate layers which withstand certain kinds of developers andtreating baths but are permeable by others or which can be madepermeable by treatment, for instance by saponiflcation.

This device of using variable intermediate layers may be used for theproduction of a new kind separate bath or simultaneously in thedeveloping operation. This component picture produced in the secondlayer is printed in the manner described above to produce the secondcolor component picture or is used directly. In case of a bil5 layersthere must be also used for the development ofthe second componentpicture a developer which does not attack the separating layer lyingbetween the second and the third emulsion layers. Fromthe secondcomponent picture in such a of exposure material which, in the techniqueof three-layer iilm there is made a copy on an auxilexposure does notdiier from the simplicity of the known bi-pack but yields, however,threecolor. components in a simple manner. This invention consists in aprocess which uses, in its simplest form, two lms, layer to layertravelling through the camera, of which lms one carries a singleemulsion layer and the other two superimposed emulsion layers, thelatter being sepa'- rated by an intermediate layer of the above kindwhich may also serve as a filter layer. Instead of two lms a single onemaybe used which carries three superimposed layers, each separated fromthe other by an intermediate-layer of the above kind, which, if desired,may also serve as iilter layers.

The essence of the invention resides in the fact that individual layersare treated in such a manner that it is possible to obtain separatelythe component color pictures from the material. Two courses arepossible. In the iirst, after exposure, which may occur in an ordinarycinematograph camera, iirst the top layer oi the two or threesuperimposed layers is developed in a developer which leaves unaffectedthe under-lying intermediate layer and in consequence also the emulsionlayers under-lying that intermediateY A Then, if desired, after dryingthe layer. the blackand-white image in the upper layer is copied on anauxiliary illm by means oi' light of a color for which the stillundeveloped layer or layers of the nlm is or arev not sensitive. Alterthis first 86 and is protected from the access of false light in Thesecond course for obtaining. the component pictures separatesthecomponents produced in the several layers, not by successive copyingsbut by the diierence'in their spectral properties. In this `procedureone may, for instance, tone the top layer after the development or onemay develop 'by means of a developer which immediately or afterseparation of the sil- .30- ver image yields a color picture by theprocess of color development or by the silver anti-diazotate process.Then, in the manner described above,

the intermediate layer-is made permeable. The

under-lying layer is developed and toned in another color. 'I'hiscoloringneed not have any 40 copy are to be obtained.

The following example 'when taken with the accompanying self-explanatorydrawing, Fig. 1 of which shows a bi-pack raw iilm -and Fig. 2 of whichdepicts the processing thereof, illustrates the invention:

A bi-pack is used in which the 'front illm carries two layers separatedby an intermediate layer which isimpermeable to an acid developer. Thelayer next to the illm is sensitive only to blue light, the superimposedlayer is sensitive to green light and is protected from the eilect ofblue rays by a yellow coloring of the whole layer or by a yellowcoloring oi the intermediate layer. The rear iiim is a panchromatic orred-sensitive illm known manner by a red iilter layer. ,Moreover, it ispreferable to provide anti-halation by a nonactinic coloring of the filmsupport. The ex posure in the camera is as usual, the layers beingtowards each other. After the exposure `-the rear nlm is developed inthe usual manner; the front lm is developed by an acid developer, forinstance bythe known ferrous oxalate developer wherebyA a picture isproduced only in the top layer. After development the image is ilxed.However, this iixing mayV -be omitted without auectlng the process,

The green component thus produced in the top layer is now copied withthe v aid of light lackingblue on an intermediate iilm sensitive togreen or red light, whereby a positive or if ldesired a reversalnegative is obtained which may be used as the second of the componentsfor producing a color picture. The original negative in the top layer isremoved .with the aid ci hot water mechanically or`by means of a solventfor silver' chemically. Then follows the development of the -secondblue-sensitive layer with the aid of an developers,.the lower ispermeable only for acid developers. First the upper emulsion layer isdeveloped by means of the ferrous oxalate developer which does notpenetrate the firstV separating layer and the intermediate positive isobtained, then. this separating layer is made permeable by an alkalineintermediate bath or the second emulsion layer is developed in an alkafline developer which cannot penetrate the second separating layenFinally the acid developer is 'again used, whereby the second separatinglayer i. A process of producing photographicl color component pictureswhich comprises exposing a 'b1-pack consisting of a single layer rearillm and of-ga front nlm carrying two differently opticallysensitizedsilver halide emulsion layers separated by anfintermediatelayer which is impermeable4 for certain developers, developing the upperlayer`oi'thefront film with adeveloper to which the intermediate layeris not permeable, copying the developed silver imge by means of lightwhich is non-actinic to the still undeveloped layer, removing the upperlayer, treating the intermediate layer in a medium which renders itpermeable to the following developer; developing the lower layer -andprintingthedeveloped silver image.

2. A process oi producing photographic color component pictures whichcomprises exposing a bi-pack consisting of a single layer rear nlm andot a front iilm carrying two diiierently optically -sensitized silverhalide emulsion layers separated by an intermediate layer which isimpermeable termediate layer is permeable and printing the developedsilver image.

3. A process of producing photographic color component pictures, whichcomprises exposing a multi-layer lm. the single silver halide emulsionlayers of which are diierently optically sensitized and separated byintermediate layers impermeable for certain developers, in such a mannerthat each sin'gle emulsion layer obtainsa component image, developingthe uppermost emulsion layer with a developer .which isunable topenetrate the `is made permeable and the third emulsionY layer .odeveloped.

underlying intermediate layer, printing the silver image of saiddeveloped layer on a suitable photographic material, removing theuppermost emulsion layer, making permeable the intermediate layer anddeveloping the second emulsion. layer, and repeating the same operationsfor the following layers.

.4. A process of producing photographic col'or component pictures, whichcomprises exposing a multi-layer lm, the single silver halide emulsionlayers of which are differently optically sensitized and separated byintermediate layers impermeable to certain developers, in such a mannerthat each single emulsion` layer obtains a component image, developingthe uppermost emulsion layer with a developer which is unable vtopenetrate the underlying intermediate layer,

printing the silver image of said ldeveloped layer on'a suitablephotographic material, removing `the silver image, making permeable saidintermediate layer, developing the second emulsion layer and repeatingthe same operations for the`

